▲ Hydroxypropyl methyl cellulose (HPMC) is an odorless, tasteless, non-toxic white powder. After fully dissolving in water, hydroxypropyl methyl cellulose will form a transparent viscous colloid.

▲ The main raw materials of hydroxypropyl methyl cellulose (HPMC): refined cotton, methyl chloride, propylene oxide, and other raw materials, caustic soda, acid, toluene, isopropanol, etc.

Comparison of the advantages and disadvantages of hydroxypropyl methyl cellulose:
1.Pure hydroxypropyl methyl cellulose HPMC is loose visually and has a small bulk density, with a scale of 0.3–0.4/ml.
The adulterated HPMC has very good fluidity and feels heavier, which is significantly different from the genuine product in appearance.
2.Pure hydroxypropyl methyl cellulose HPMC aqueous solution is clear, high light transmittance, water retention rate > 97%.
The adulterated HPMC aqueous solution is relatively dirty, and the water retention rate is difficult to reach 80%.
3.Pure HPMC should not smell of ammonia, starch and alcohols.
Adulterated HPMC can usually smell all kinds of flavors, even if it is tasteless, it will feel heavy.
4.Pure hydroxypropyl methyl cellulose HPMC powder is fibrous under a microscope or magnifying glass.
Adulterated HPMC can be observed as granular solids or crystals under a microscope or magnifying glass.

From what aspects to identify the advantages and disadvantages of hydroxypropyl methyl cellulose?
1.white degree
Although whiteness cannot determine whether HPMC is easy to use, and if whitening agents are added during the production process, it will affect its quality. However, most of the good products have good whiteness.

2.Fineness
The fineness of HPMC generally has 80 mesh and 100 mesh, and the finer the fineness, generally speaking, the better.
3.Transmittance
Put hydroxypropyl methyl cellulose (HPMC) into water to form a transparent colloid, and check its light transmittance. The higher the light transmittance, the better, indicating that there are less insoluble substances in it. The permeability of vertical reactors is generally good, while that of horizontal reactors is worse.

4.Proportion
The larger the specific gravity, the heavier the better. The specificity is large, generally because the content of hydroxypropyl group in it is high, and the content of hydroxypropyl group is high, the water retention is better.